The present invention relates to heat transfer labels. More particularly, the present invention relates to a selectively metallized heat transfer label that allows the selective transfer of a metallic finish section of the label along with the transfer of a non-metallic ink section of the label in a single-step label application process.
Labels are in widespread use in most every industry. For example, labels are used to transfer indicia onto goods, including consumer items ranging from cell phone cases to golf club shafts. Typically, labels consist of thermoplastic color layers capable of being adhered to substrates upon application of heat and pressure. Many of the items to which the indicia are applied are rigid, or semi-rigid, thus allowing the label transfer to be carried out using heat transfer methods.
It is of utmost importance that the indicia or marking transferred to the item is of a high quality. In many instances, the item is one that is intended to be used for a long period of time. For example, cellular telephones are intended to last for at least a number of years, as are golf clubs. To this end, the printed indicia (e.g., the manufacturer's name, trademark or the like), should be long-lasting, difficult to abrade and resistant to chemical and environmental degradation.
Additionally, it is desirable in some applications that the label has a metallized finish section once the label is applied to the goods. The prior art has adopted various techniques to achieve the desired metallized effect.
In a known sequential technique, a standard metallic hot stamp foil is used, and the metallic portion of the indicia is transferred to the substrate using a hot stamp machine. The non-metallic portion of the indicia is then applied to the substrate using any number of prior art methods, such as pad printing or direct screening printing, or simply using a standard heat transfer label. However, this technique may be more expensive and time-consuming, requiring a multi-step process to achieve the desired effect.
A second technique used by the prior art is to selectively demetallize a film, print the non-metallic indicia on the selectively demetallized areas of the film and transfer the resulting label using standard heat transfer equipment. In this technique, a protective mask is printed on a vacuum metallized aluminum foil layer. The protective mask is printed on the foil in the shape of the desired metallized portion of the indicia. The foil layer then is demetallized by printing a caustic paste across the entire film and passing the film through a water bath to remove the aluminum layer from the film. In this manner, the aluminum foil layer remains in the areas that were covered by the protective mask. The non-metallic portion of the indicia is then printed in the areas of the label where the aluminum foil layer has been removed, and the label is applied to the substrate using traditional application methods. While this technique, unlike the preceding technique, allows for the label to be applied to the substrate in a one-step process, the necessary use of a caustic wash, and the additional cost required to treat the wastewater resulting from the caustic wash, make the use of this technique less desirable.
Accordingly, there exists a need for an efficient and high quality selectively metallized heat transfer label that allows the selective transfer of a metallic finish section of the label along with the transfer of a non-metallic ink section of the label. Desirably, such a label is chemically resistant to numerous environments. More desirably, such a label is made without the use of a caustic wash. Most desirably, such a label is applied to a substrate in a single-step application process and results in a clean, crisp transfer of the metallic section of the label.